La Buse variable

Forsman (2016) writes about Common Buzzard Buteo buteo: Highly variable, with several subspecies described for the Western Palearctic, exhibiting extensive but poorly understood geographical variation in plumage, size and structure. Nominate buteo from southern Scandinavia and western and central Europe can be divided into three main colour morphs (dark, intermediate and light), though various intergrades add to the variation.

The status of Steppe Buzzard B b vulpinus in the Netherlands has been controversial for a long time. The subspecies was placed on the Dutch list based on several old specimens and a number of undocumented field observations. However, after a revision the majority of these records were no longer considered acceptable (van Duivendijk 2011).

Currently, there are two records of Steppe Buzzard on the Dutch list. The first refers to an adult male collected at Hof van Twente in Overijssel on 16 April 1902, the second to an adult male collected at Valkenburg aan de Geul in Limburg on 11 April 1918 (not 1908, as mentioned in van Duivendijk (2011)). The status of a first-winter female collected at Deurne in North Brabant on 10 November 1908
, was somewhat unclear. The annual report on rare birds in the Netherlands stated that this specimen too remained acceptable after revision (Ovaa et al 2009), however, little later it was rejected after all (van Duivendijk 2011). Note that both Ovaa et al (2009) and van Duivendijk (2011) mentioned wrong dates for this record (10 November 1902 and 16 November 1908, respectively).

Adult Common Buzzard showing rufous tail (Spaarnwoude, 1 February 2021). Although a rufous tail with fine, distinct barring and a wider subterminal band will support the identification of many Steppe Buzzards, claiming this subspecies away from its normal range is usually not possible because of the immense plumage variation in Common and Steppe Buzzard. The identification of both Steppe Buzzards on the Dutch list is strongly based on biometric characters, such as the width of the central tail feathers in adults.

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Published 2 February 2021